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S L Dawson

Publications and source records attributed to S L Dawson.

At least 55 records · Page 3Linked to original sources
PubMed1993

CT-guided celiac ganglion block with alcohol.

Celiac ganglion block has been performed without radiologic guidance by surgeons or anesthetists since it was first described by Kappis [1] in 1914. Radiographic guidance for celiac block was first reported in the 1950s [2], and more recently, radiologists have used CT to guide needle placement [3-5]. With CT guidance, more directed positioning of the needle is possible, allowing alcohol to be deposited in the specific ganglion areas. This article reviews our collective experience with CT-guided celiac ganglion block.

Autonomic Nerve Block↗
PubMed1993

Efficacy of sonographically guided biopsy of thyroid masses and cervical lymph nodes.

OBJECTIVE: We performed a prospective study in 96 patients to determine accuracy of sonographically guided fine-needle aspiration biopsy of thyroid masses and cervical lymph nodes. MATERIALS AND METHODS: Real-time sonography was used to guide biopsy of 112 cervical masses in 96 patients (71 patients with impalpable masses, 16 with failed unguided attempts, patient's or physician's preference in nine). The diameters of all masses were less than 3 cm, with a mean of 1.5 cm and a median of 1.5 cm. Twenty-nine masses measured 1 cm or less in diameter, 60 masses between 1.1 and 2.0 cm, and 23 masses between 2.1 and 3.0 cm. Cervical masses that were sampled by biopsy included 75 thyroid masses and 37 lymph nodes. RESULTS: Diagnostic specimens were obtained in 102 (91%) of 112 masses sampled. Sixty-eight (91%) of 75 biopsies of thyroid tissue and 34 (92%) of 37 biopsies of lymph nodes were diagnostic. Nondiagnostic thyroid biopsies included four of complex cysts and three of solid nodules. Sonographic follow-up (1 year) revealed no change or decrease in size of those seven lesions. Sixty of 68 diagnostic thyroid biopsies showed benign processes: 42 macrofollicular adenomas, six colloid adenomas, five microfollicular adenomas, four probable cases of thyroiditis, and three hemorrhagic cysts. The remaining eight diagnostic thyroid biopsies showed malignant processes: seven papillary carcinomas and one metastatic small-cell carcinoma. Of 34 diagnostic biopsies of lymph nodes, 26 showed malignant processes and eight showed benign processes. Surgery in the three patients with nondiagnostic biopsies of lymph nodes revealed two recurrent medullary cancers and one benign node. CONCLUSION: Sonographically guided fine-needle aspiration biopsy of neck masses has a high sensitivity (91%) and should be routinely used to evaluate indeterminate masses in the neck.

Adult↗
PubMed1992

Palliation of malignant bile duct obstruction with metallic biliary endoprostheses: technique, results, and complications.

Expandable metallic stents were placed in 34 patients with pathologically proved malignant bile duct obstruction to determine ease of insertion, benefits of a one-stage insertion, and cost-effectiveness relative to conventional plastic stents. Thirty-eight strictures, ranging in length from 1 to 7 cm (mean, 3.2 cm), were present in the 34 patients. Strictures were located in the lower common bile duct (n = 22), middle of the common bile duct (n = 6), and hilar confluence (n = 10). In 13 patients (38%) metallic stents were placed at the time of initial biliary drainage (one-stage procedure), while the remaining patients underwent stent placement within 1-7 days of biliary drainage (two-stage procedure). Biliary obstruction was relieved in 31 of 34 patients (91%). Three patients died within 14 days of stent insertion of unrelated causes, without any change in biliary status. Mean duration of follow-up for all patients was 5.3 months (range, 0.5-14 months). Four episodes of stent occlusion occurred in three patients (12% occlusion rate); each episode was treated successfully. The average length of hospital stay for patients who underwent a one-stage procedure was 13 days (range, 3-33 days) and was 20 days (range, 9-42 days) for patients who underwent a two-stage procedure. The facility of one-step insertion, low occlusion rate, and the many strategies available for treatment of occluded stents make metallic stents an attractive alternative to conventional plastic stents in palliating patients with malignant biliary obstruction.

Adenoma, Bile Duct↗
PubMed1992

Acute complicated pancreatitis: redefining the role of interventional radiology.

Computed tomographic (CT) scans in 30 patients who had undergone percutaneous drainage for acute complicated pancreatitis were retrospectively studied to determine the role of percutaneous drainage. Fifty-nine collections were percutaneously drained in these 30 patients. Eighty-one catheters were placed in the 59 collections (average, 1.4 catheters per patient). Patients required an average of three catheter manipulations, seven abdominal CT scans, 5 weeks of catheter drainage, a mean hospital stay of 82 days (range, 42-122 days), and a mean intensive care unit stay of 31 days (range, 1-62 days). Percutaneous intervention was successful in 14 patients, partially successful in four, and unsuccessful in eight. A temporizing effect was seen in four patients. Percutaneous intervention was successful in one of 10 central (pancreas and lesser sac areas) collections and 28 of 49 peripheral collections. Surgical debridement was necessary in 16 patients because of failed or incomplete percutaneous drainage. Complications occurred in five patients, and the mortality rate was 33%. Drainage of central areas should initially be performed by a surgeon, while peripheral collections should be drained percutaneously as they develop.

Acute Disease↗
PubMed1992

Measurement of tissue carcinoembryonic antigen levels from fine-needle biopsy specimens: technique and clinical usefulness.

Levels of tissue carcinoembryonic antigen (CEA) in 54 abdominal fine-needle biopsy specimens from 50 patients were measured to ascertain the use of tissue CEA levels in diagnosis of malignancy. Biopsy was performed in the following sites: liver (n = 34), retroperitoneum (n = 8), adrenal gland (n = 3), pancreas (n = 2), omentum (n = 2), pelvis (n = 2), spleen (n = 2), and stomach (n = 1). Histologic findings proved malignancy in 39 patients and benign disease in 11 patients. In these 11 patients, the mean levels of tissue CEA were lower than the normal level of serum CEA (3 ng/mL). Tissue CEA levels were higher than serum CEA levels in nine patients with colonic carcinoma and in 12 of 16 patients with noncolonic CEA-secreting malignancies. Four patients with noncolonic CEA-secreting malignancies had tissue CEA levels within the normal range (less than 3 ng/mL). Tissue CEA levels were also normal in 13 patients with various non-CEA-secreting tumors. Tissue CEA levels may prove useful in biopsy of necrotic or cystic lesions and assessment of response to ablative therapy for colon metastases.

Adult↗
PubMed1992

Wallstent metallic biliary endoprosthesis: MR imaging characteristics.

Image quality and safety of magnetic resonance (MR) imaging were evaluated in vitro and in eight patients with the most commonly employed metallic biliary endoprosthesis. In vitro, the stent produced no tip deflection at 0.6 or 1.5 T. Trace magnetic susceptibility artifact, similar to artifact from a column of air, paralleled the stent. In patients, image degradation was minimal with conventional pulse sequences. Middle-field-strength spin-echo images revealed minimal artifacts indistinguishable from those produced by pneumobilia.

Biliary Tract↗
PubMed1992

Sclerotherapy of malignant pleural effusion through sonographically placed small-bore catheters.

Pleural sclerosis after drainage with a small-bore catheter was performed in 21 patients with malignant pleural effusions. Intrapleural catheters 7- to 24-French in size were placed by using sonographic guidance. Tetracycline (18 patients) and bleomycin (four patients) were used as sclerosing agents (one patient had both). Clinical and radiologic follow-up was available on all patients until they died (range, 2 weeks to 25 months; mean, 3.6 months). Pleural sclerosis was successful in 15 (71%) of 21 patients. Two patients in whom pleurodesis failed had pleural sclerosis repeated, with one success and one failure. All of the failures were in patients in whom the amount of chest-tube drainage was more than 100 ml/day. Pleurodesis with tetracycline was painful in six patients; no pain was associated with use of bleomycin. Small pneumothoraces developed in four patients at the time of chest-tube placement, without consequence. A superimposed infection that developed in a patient having continuous drainage of pleural fluid was successfully treated with antibiotics. Pleural sclerotherapy can be performed through sonographically placed small-bore catheters with results comparable to those seen with large-bore, surgically placed catheters.

Adult↗
PubMed1992

Treatment of bile duct stones by laser lithotripsy: results in 12 patients.

We used a pulsed tunable dye laser (operating at 60 mJ per pulse, 504-nm wavelength) to fragment large (0.8-4.5 cm) stones retained in the hepatic ducts or common bile duct in 12 patients after cholecystectomy. Attempts to extract stones via a T-tube or endoscope had been unsuccessful in all patients. In nine of 12 patients, all stone fragments were successfully eliminated during the initial treatment. In one patient, fragmentation occurred but debris remained, requiring endoscopic stenting. Pseudomonas sepsis developed in this patient 30 days after the procedure and was treated by extraction of the stone fragments. Fragments remaining after lithotripsy were cleared at the same sitting by using saline flushing or endoscopic or percutaneous basket extraction. In two of 12 patients, the treatment was unsuccessful because of laser malfunction. The treatment was performed without complications, except for clinically insignificant hyperamylasemia, which occurred in two patients. Our experience suggests that laser lithotripsy offers a safe alternative for nonsurgical treatment of large retained biliary stones for patients in whom traditional treatments have failed.

Aged↗
PubMed1991

Percutaneous contact dissolution of gallstones: complexity of radiologic care.

The clinical and technical considerations for successful gallstone dissolution with methyl tert-butyl ether (MTBE) are often underestimated. Patients are selected for MTBE therapy on the basis of a functioning gallbladder without evidence of acute inflammation or calcified stones at plain radiography. A transhepatic route is favored for percutaneous insertion of the cholecystostomy catheter because of the theoretic reduced frequency of bile leakage. MTBE is delivered manually through the catheter in a closed system, with dissolution times of 4-16 hours. After MTBE dissolution, residual debris in the gallbladder is present at follow-up sonography in up to 75% of patients. The high frequency of residual debris, the potential for stone recurrence, and the labor-intensive nature of MTBE therapy make its future uncertain, especially with the advent of laparoscopic cholecystectomy.

Cholelithiasis↗
PubMed1991

Importance of daily rounds by the radiologist after interventional procedures of the abdomen and chest.

A prospective study was performed to evaluate the clinical utility of daily rounds by the radiologist for patients with indwelling catheters in the chest and abdomen, placed during interventional radiologic procedures. The 7-week evaluation included documentation of the number of patients seen, time spent with each per day, number of problems identified, management of these problems, and consultations for new cases generated by interaction with other staff. During the 268 visits to 37 patients, 59 catheter-related problems were identified; 17 (29%) required further intervention in the radiology department, and 42 (71%) were managed at the patient's bedside. Of the patients who were followed up, 22 (59%) had some catheter-related problem identified during their hospital stay. Daily rounds by the radiologist are an essential component of patient care after catheter-related interventional procedures and should be made by those who perform and understand the procedures.

Catheterization↗
PubMed1991

Percutaneous dilatation of benign biliary strictures: single-session therapy with general anesthesia.

Percutaneous biliary stricture dilatation (PBSD) is an uncomfortable procedure for patients that presently requires multiple dilatation sessions spread over many days. We evaluated the use of general anesthesia to enable PBSD to be performed in a single sitting in 14 patients with benign biliary strictures (11 anastomotic and three iatrogenic strictures). Four patients had multiple strictures, and the other 10 had a single stricture. Strictures were documented by transhepatic cholangiography (11 patients) or T-tube cholangiography (three); quantitative biliary perfusion studies were additionally performed in seven cases. Dilatation was performed transhepatically in 11 patients and via a T-tube track in three. Balloons ranged from 8 to 12 mm in diameter and were manually inflated for 3 min with an average of five inflations per stricture. Stenting catheters were left across the strictured areas in all patients for 6-21 days (mean, 10 days) before removal. The mean duration of hospital stay for all patients was 5.7 days, which could further be divided into means of 3.6 days (range, 1-6 days) for 11 patients without complications and 13.7 days (range, 13-14 days) for three patients who had complications. Complications included cholangitis; liver hematoma (which resolved with conservative therapy in both cases); and pseudoaneurysm of the hepatic artery, which necessitated angiographic embolization. PBSD achieved long-term patency in 13 (93%) of 14 patients with a follow-up period of 2.0 to 5.5 years (mean, 3.2 years). A stricture recurred in one patient 1.5 years after dilatation. We conclude that PBSD with the patient under general anesthesia can be performed in a single visit to the radiology department with excellent long-term patency rates, a shorter hospital stay, and a pain-free procedure for the patient.

Adolescent↗
PubMed1987

Sigmoid diverticular abscesses: percutaneous drainage as an adjunct to surgical resection in 24 cases.

Twenty-four patients with acute sigmoid diverticulitis and associated pelvic fluid collections seen on computed tomographic scans underwent percutaneous catheter drainage as an adjunct to surgical therapy. Fourteen of the 24 underwent a single-stage surgical procedure within 10 days of drainage. Five patients required two-stage surgical procedures because localized inflammatory changes precluded a primary resection despite the absence of a residual abscess at surgery. Two of the three remaining patients initially had no surgery, but they had recrudescences of their symptoms that required surgical drainage within 8 months. One patient in whom surgical resection was deferred remained asymptomatic 10 months after percutaneous drainage. A retrospective review of 87 patients undergoing surgery for diverticulitis suggested that the percentage of two-stage surgical procedures has decreased in the last 5-10 years, but there remains a substantial number of patients who might benefit from percutaneous catheter drainage of diverticular abscess of the sigmoid colon.

Abscess↗
PubMed1985

Insertion of a biliary endoprosthesis using a balloon dilatation catheter.

Adequate function of a percutaneous biliary endoprosthesis is accomplished by its successful positioning through the site of obstruction. Stent insertion is greatly facilitated when a peripheral bile duct is entered parallel to its long axis or the stent angled in a caudal direction. When the biliary system is entered in a cephalad direction, insertion may be laborious and a mature tract is often required. We describe the technique for such a positioning of a large-bore, long endoprosthesis using a vascular balloon dilatation catheter.

Catheterization↗
PubMed1985

Nonoperative management of biliary obstruction.

Nonoperative therapy of biliary obstruction is a viable alternative to surgical therapy, particularly in patients with malignant obstruction, in whom prognosis is generally poor. Radiologic techniques can now define the extent and etiology of biliary obstruction, provide palliative drainage, and allow derivative nonoperative procedures to be performed. This chapter provides an introduction to the role the interventional radiologist may play in the therapy of patients with obstructive jaundice.

Bile Duct Neoplasms↗
PubMed1985

The bile ducts after a fatty meal: further sonographic observations.

The sonographic appearance of the response of the common hepatic duct to physiologic stimulation by a fatty meal was assessed in 131 patients referred because of right upper quadrant symptoms or abnormal liver chemical studies. In the determination of the presence or absence of biliary obstruction, the sensitivity of the examination was 84%, the accuracy of a positive test was 84%, and the accuracy of a negative test was 93%. This test proved helpful in several circumstances: equivocal duct caliber (6-10 mm); abnormal caliber (6-14 mm) with normal laboratory values; normal caliber duct with abnormal laboratory values; persistent question of cholelithiasis or asymptomatic pancreatic duct dilatation. Measurements of bile duct caliber alone may be insufficient to ascertain the presence of bile duct obstruction and fatty meal stimulation significantly improves diagnostic accuracy.

Bile Ducts↗
PubMed1985

Hepatic echinococcal cyst: successful percutaneous drainage.

Percutaneous needle aspiration of hydatid cysts has long been discouraged because of potential complications, such as anaphylactic shock and the spread of daughter cysts. We used this procedure with successful results, however, in the treatment of a woman with a recurrent hepatic hydatid cyst. The cyst was drained percutaneously using radiologic imaging guidance and then lavaged through a catheter using silver nitrate and hypertonic saline solutions. One year after drainage, all liver function test results remain normal. Although surgical drainage is normally the treatment of choice for hepatic Echinococcus disease, percutaneous catheter drainage may be an alternative therapy for patients who cannot undergo surgery.

Aged↗